Rutger Hauer Or Uma Thurman?

[372xp]

So my question is this. Do I have a benign hitchhiker here or a murderous psychopath? The reason I ask is 1 death and a change in behaviour. This morning my firefish was dead, and with cunning use of powerheads and a small dismantle I wafted him out from behind the rocks. He had been crabbed a bit so I just flushed him without a proper look. Secondly my Red Stripe angel has been acting strangely in the last few days. She is a bit of a coral nipper and will try most things but soon gives up on them in favour of seaweed (except for xenias which are now all gone). I am wandering if she has nipped these hitchers and been stung or they have made her sick. My last hitchers were and still are little beauties, some sort of nudibranch with an insatiable appetite for hair algae, but these "anenomes" I'm not so sure, they have already been bothering my hairy mushrooms.
Any ideas, pictures below.

 

[Donya]

Those are unfortunately majano anemones, which are rather potent pests will irritate and/or kill corals they bump up against. 
 
Keep an eye on the fish you said was acting odd; it is very possible that it nipped something that was a bit too spicy for it. Similarly, fish that accidentally nip bristleworms often act weird and skiddish for a few days afterwards. However, the firefish being dead soon before the behavior change is a bit suspicious. I would not suspect the majanos of having caused the death. 

 

[372xp]

Manjano? I thought they had slightly bubble tipped tentacles. The smaller orangy/brown one folds up at night the greeny ones dont. The orangy one also has a stem whereas the green ones dont. I thought they could be tulip anenomes, I agree with you on the brown one.
Next question is erradication. Will a lethal injection of aiptasia x deal with these? Then do I have to get rid of the dead bits?

 

[Donya]

Anemones will change shape depending on flow, light, and many other factors, so Majanos don't always have bubbled tips (just like BTAs don't always bubble). I've always found Joe's Juice to be better at getting rid of pest anemones than Aiptasia-X, particularly when they're large, but if you've only got the one on hand it's worth a shot. In a worst case they'll just go back into a hole in the rock for a while and you'll have to toast them again later. The dead bits are basically impossible to get rid of cleanly (try a turkey baster to suck it out, but IME that's hit and miss), so that's one reason why products like those tend to recommend doing a bit at a time rather then trying to do whole-tank eradication in one go. 

 

[ech0o]

There are 2 diff nems in this pic, the bottom one seems like a harder stinger to me, although the others are def. majano